When sending a marketing email, the subject line is your first—and sometimes only—opportunity to grab your recipient’s attention.
A poorly crafted subject line can land your email in the spam folder, while a compelling one can entice the recipient to open and engage with your content. Here’s how to write subject lines that not only bypass spam filters but also drive engagement.
Understanding Spam Filters
Spam filters are designed to protect users from unwanted or potentially harmful emails. They use algorithms to scan subject lines and email content, flagging messages that contain certain characteristics. Common red flags include:
· Excessive use of capital letters (e.g., “BUY NOW!!!”)
· Overuse of punctuation (e.g., “Best Deals!!!!”)
· Spam-triggering keywords like “Free,” “Urgent,” “Cash Bonus,” “Limited Time Offer,” or “Act Now”
· Misleading statements or clickbait tactics
· Poor grammar and spelling errors
To avoid getting caught in spam filters, ensure your subject line is clear, relevant, and free of these red flags.
Tips for Writing Effective Subject Lines
· Keep It Concise
Shorter subject lines (ideally 5–7 words) tend to perform better. Many email clients cut off subject lines after 50-60 characters, so make sure the key message is upfront.
· Avoid Spam Trigger Words
Certain words are frequently associated with spam and can negatively impact deliverability. Instead of saying “Get a Free Gift Now!”, try “Your Exclusive Offer Inside” or “Here’s a Special Gift for You”.
· Personalization Works Wonders
Emails with personalized subject lines are more likely to be opened. Include the recipient’s name or reference something specific about their industry or interest. Example: “John, Here’s Something Just for You”.
· Create a Sense of Urgency—Without Being Spammy
Urgency can drive engagement, but using all caps and excessive punctuation can flag spam filters. Instead of “ACT NOW! Limited Time!”, try “Last Chance: Offer Ends Tonight”.
· Use Numbers and Statistics
Numbers add credibility and make subject lines stand out. Example: “5 Ways to Boost Your Sales Today” or “How 3 Simple Steps Can Improve Safety”.
· Ask an Intriguing Question
Subject lines in question format can pique curiosity. Example: “Are You Protecting Your Employees the Right Way?” or “What’s Missing in Your Safety Plan?”.
· Avoid Excessive Symbols and Emojis
While a well-placed emoji can enhance visibility, too many symbols (like dollar signs $$$ or emojis 🎉🎁🔥) can make your email look like spam. Keep it minimal and relevant.
· Test Your Subject Lines
A/B testing can help determine what resonates best with your audience. Try sending two variations to a small segment of your list and see which performs better before rolling it out to everyone.
· Make It Relevant and Valuable
Your subject line should clearly indicate what’s in the email. If the recipient doesn’t see the value, they won’t open it. Example: “How to Cut Business Costs Without Sacrificing Quality”.
· Avoid Clickbait—Be Honest!
Misleading subject lines damage trust and lead to high unsubscribe rates. If your subject line promises “A Free Guide Inside”, make sure that’s exactly what they’ll get.
Examples of Engaging Subject Lines That Work
✅ “Boost Your Productivity with These 3 Tips” ✅ “John, Your Exclusive Safety Report is Ready” ✅ “How Companies Save 20% on PPE Costs” ✅ “Your Custom Marketing Plan—Let’s Talk” ✅ “Top Industry Insights You Need to See”
Final Thoughts
A great subject line is the gateway to a successful marketing email. By avoiding spam triggers, making your subject line engaging yet professional, and adding personalization, you’ll increase your chances of getting your emails opened and read. Take the time to test different strategies and optimize for the best results. Happy emailing!